Inner roofing.



PATENTED FEB. 26, 1907.

A. KIEFBR. INNER ROOFING. APPLICATION FILED NOV. 16. 1905.

ADOLF KIEFER, or HEIDELBERG, GERMANY.

-- INNER ROOFING.

Specification of Letters Patent.

Patented Feb. 26, 1907.

Application filed November 16. 1905. Serial No. 287.585.

To all whom. it may concern-- Be' it known that I, ADOLF KI-EFER, a citizen of the German Empire, residing at Kron prinzenstrasse 6,. Heidelberg, Baden, Ger:

many, have invented new and useful Improvemcnts in' Inner Roofingflof which the following is a specification.

This invention relates to specially-constructed concrete junction-slabs rovided with tie-wings, by means whereof wit the introduction of one or more iron rods. and a wedge shaped filling of cement mortar between their opposing end surfaces a firm union of suchslabs is efl'ected, forming a massive selfbearing inner roof or ceiling. The accompanying drawings displayan example of this concrete junction-slab as constructed and the mode in which the conjoining of two of these slabs is secured.

Figure 1 is a perspective representation of a junction-slab with its mountings. Fig. 2

gives a cross-section at the point of junctionof two such slabs where a single iron bar is used; andFig. 8, the same, but. where two. bars and clamps are used. n

cis a concrete junction-slab having a number of transverse openings running through from side to side, with floors 0 somewhat below its center; The surfaces a may be plain or cut into grooves and studs, and they come ,squarely together in the ceiling. The surdaces c are perpendicular for a certain distance from.the bottom and then run obliquely back, as shown in Fig. l, in a single ther inward and then brought outward again to such original inclination. An oblong sheet of stout wire-networkis bedded in the wetconcrete whilethe junction-slab is being con structed. It is set above the under surface of such. slab andbclow the floors 0, whatever transverse openings may be molded'therein; The end of this wire-network sheet, whichprojects at each end of the slab, forms a tie f wing b. These tie-wings b are bent upward at right angles,fn'st perpendicularly, then in an outward sweep, and finally man inward. V

' duce a wedgeshapedgroove between each adjoining pair, mortar in the said wedge 105' this is considered sufficient, a single'round 'iron bar 0 laid centrally between the opposing lower surfaees of the junction-slabs in what may be termed the region of strain.

the region of strain.

"are'bent upwardly to he wit The space between the two slabs is filled in with cement mortar d. Owing to thespec'ial construction of the slabs, this filling of cement mortar, as shown in Figs. 2 and 3, is given the shape of a wedge. When such wedge is hardened, it holds the tie-Wings, and iron bars securely. embedded along its entire length and forms a binding adequate to resist any strain and to bear any load involved.

In place of a single bar two rod iron bars are used in cases where it is considered needful to counteract any lateral'pressure on the abutments which may arise. They are laid fronting the lower parts of the surfaces a? in Each bar is setin the corner formed by the bending upward at right angles of the tie-wings b, as seen in Fig. 3. There they are held firmly fixed at a certain distance each from each by clamps e at suitable intervals. When the filling d has set, they are maintained thus'in position and lateral pressure against the abutments caused by loading of the, inner roo f is effectively counteracted. So constructed and put together each slab forms an integral portion of a totalvsingle inner roof or ceiling. If circumstances render it desirable or convenient, such inner roof or. ceiling of one story or chamber may form the floor of the story or chamber next above. An absolutelyfsecure inner roofing .or ceiling or flooring is thus 'created and wholly self bearing. No joists nor beams nor pillars nor props of any kind are needed for its support. They are made wholly superfluous, while at the same time pressure of load andcoinpressive strain are effectually met. Such inner roofing or ceiling can be producedzas above to awidth of ten meters. Its simplicity assures a low cost.

price and' yields immense technical advan- .tages.

What I claim as my invention, and desire to protect by Letters Patent, is

1. A ceiling of concrete and iron O01'npris---Ioc ing a number of junction-slabs of concrete laid in abut ting relation, the abutting joints of thes'aid slabs being beveled so as to prothe mortar in the wedge-shaped grooves and the pressure zone of-the floor.

2, A ceiling of-concrete and iron comprise in the region of g m .1

ing a number of junction-slabs of concretelaid in abutting relation, the abutting joints sure zone of the floor, an iron rod situated over said wire-netting reinforcement Where is projects forth from the slab, and clamps connecting the iron rods of neighboring slabs.-

In witness whereof I have hereunto signed my name in the presence of two witnesses.

' ADOLF KIEFER. Witnesses:

H. W. HARRIS, .Jos. H. LEUTE. 

